Aim:. To determine if patients with coronal plane deformity in the lumbar spine have a higher grade of lumbar spine subtype compared to controls. Method:. This was a retrospective case/control study based on a review of radiological investigations in 250 patients aged over 40 years who had standing plain film lumbar radiographs with hips present. Measurements of lumbar coronal plane angle, lumbar lordosis, sacral slope, pelvic tilt and pelvic incidence were obtained. “Cases” with degenerative scoliosis (n=125) were defined as patients with a lumbar coronal plane angle of >10°. Lumbar spine subtype was categorised (1–4) using the Roussouly classification. Lumbar spine subtype was dichotomised into low (type 1,2) or high (type 3,4). Prevalence of lumbar spine subtype in cases versus controls was compared using the Chi squared test. Pelvic incidence was compared using an unpaired T-test. Predictors of lumbar coronal plane angle were identified using stepwise multiple regression. Significance was accepted at P<0.05. Results:. The prevalence of type 1–4 lumbar spine subtypes in the case group were 12.8%, 20.8%, 30.4% and 36% respectively and in the control group were 10.4%, 38.3% and 28% and 23.3% respectively. Types 3 and 4 lumbar spine subtypes were more prevalent in the cases group (66.4% vs 51.2% respectively, P=0.0207). Pelvic incidence was not significant different between groups (P=0.0594). No significant predictors of lumbar coronal plane angle were determined. Lumbar spine subtype (P=0.969), pelvic incidence (P=0.740), sacral slope (P=0.203) pelvic tilt (P=0.167) and lumbar lordosis (P=0.088) were not significant. Discussion:. Results show that neither the lumbar spine subtype nor pelvic parameters appear to have a significant influence on determining the coronal plane angle in the degenerative lumbar spine. Conflict Of Interest Statement: No conflict of interest

Aim:. To simplify sagittal plane spinal assessment by describing a single novel angle in the lumbar spine equivalent to the difference between pelvic incidence (PI) and lumbar lordosis (LL) and evaluate its reliability. Methods:. New sagittal modifiers in the classification of adult degenerative spinal deformity have been shown to be valid and reliable with the greatest variability being for pelvic incidence minus lumbar lordosis (PI-LL). This measurement can be simplified to a new angle (alpha) without the need to determine either PI or LL. This angle is between a line intersecting the bicoxofemoral centre and perpendicular to the L1 endplate (alpha line) and a line from the bicoxofemoral centre to the centre of the sacral endplate. Two readers graded 40 non-premarked cases twice each, approximately 1 week apart. Inter- and intra-rater variability and agreement were determined for PI-LL and alpha angle separately. Fleiss' kappa was used for reliability measures. Results:. Inter-rater kappa for PI-LL showed substantial reliability and alpha angle showed almost perfect agreement. Intra-rater kappa showed substantial reliability for PI-LL but almost perfect agreement for alpha angle across both readers. Discussion:. Alpha angle can be used as a surrogate for PI-LL and is easier and more reliable to measure. When PI=LL, alpha angle is 0, so the alpha line bisects the sacral plate. Conflict Of Interest Statement: No conflict of interest

The lordosis distribution index (LDI) describes distribution of lumbar lordosis, measured as the % of lower lumbar lordosis (L4-S1) compared to global lordosis (L1-S1) with normal value 50–50%. Maldistributed LDI is associated with higher revision in short lumbar fusions, 4 vertebrae1. We hypothesise maldistributed LDI is also associated with mechanical failure in longer fusions. Retrospective review of 29 consecutive ASD patients, aged 55+, undergoing long lumbar fusion, 4 levels, with >3-years follow-up. LDI, pelvic incidence (PI) and sagittal vertical axis (SVA) were measured on pre- and post-op whole spine standing X-rays (Fig A and B). Patients were categorized according to their pelvic incidence (PI) and postoperative LDI: Normal (LDI 50 80), Hypolordotic (LDI < 50), or Hyperlordotic (LDI > 80) and assessed for failure rate compared to normal LDI and PI <60. Mean follow-up 4.5 years. 19 patients had mechanical failures including junctional failure and metalware fracture. PI >60o was associated with higher mechanical failure rates (Chi^2 p<0.05). Hypolordotic LDI was associated with 82% mechanical failure (Chi^2 p<0.001), Hyperlordotic 88% mechanical failure (Chi^2 p<0.001) and Normal 8% mechanical failure (Table 1). Maldistributed LDI, whether Hyperlordotic or Hypolordotic, correlated with 10× greater mechanical failure rate compared to Normal LDI in long fusions. LDI is a useful measurement that should be considered, especially in high PI patients

Aims. To describe the clinical, radiological, and functional outcomes in patients with isolated congenital thoracolumbar kyphosis who were treated with three-column osteotomy by posterior-only approach. Methods. Hospital records of 27 patients with isolated congenital thoracolumbar kyphosis undergoing surgery at a single centre were retrospectively analyzed. All patients underwent deformity correction which involved a three-column osteotomy by single-stage posterior-only approach. Radiological parameters (local kyphosis angle (KA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), C7 sagittal vertical axis (C7 SVA), T1 slope, and pelvic incidence minus lumbar lordosis (PI-LL)), functional scores, and clinical details of complications were recorded. Results. The mean age of the study population was 13.9 years (SD 6.4). The apex of deformity was in thoracic, thoracolumbar, and lumbar spine in five, 14, and eight patients, respectively. The mean operating time was 178.4 minutes (SD 38.5) and the mean operative blood loss was 701.8 ml (SD 194.4). KA (preoperative mean 70.8° (SD 21.6°) vs final follow-up mean 24.7° (SD 18.9°); p < 0.001) and TK (preoperative mean -1.48° (SD 41.23°) vs final follow-up mean 24.28° (SD 17.29°); p = 0.005) underwent a significant change with surgery. Mean Scoliosis Research Society (SRS-22r) score improved after surgical correction (preoperative mean 3.24 (SD 0.37) vs final follow-up mean 4.28 (SD 0.47); p < 0.001) with maximum improvement in self-image and mental health domains. The overall complication rate was 26%, including two neurological and five non-neurological complications. Permanent neurological deficit was noted in one patient. Conclusion. Deformity correction employing three-column osteotomies by a single-stage posterior-only approach is safe and effective in treating isolated congenital thoracolumbar kyphosis. Cite this article: Bone Joint J 2021;103-B(7):1309–1316

We investigated the spinopelvic morphology and global sagittal balance of patients with a degenerative retrolisthesis or anterolisthesis. A total of 269 consecutive patients with a degenerative spondylolisthesis were included in this study. There were 95 men and 174 women with a mean age of 64.3 years (. sd. 10.5; 40 to 88). A total of 106 patients had a pure retrolisthesis (R group), 130 had a pure anterolisthesis (A group), and 33 had both (R+A group). A backward slip was found in the upper lumbar levels (mostly L2 or L3) with an almost equal gender distribution in both the R and R+A groups. The pelvic incidence and sacral slope of the R group were significantly lower than those of the A (both p < 0.001) and R+A groups (both p < 0.001). The lumbar lordosis of the R+A group was significantly greater than that of the R (p = 0.025) and A groups (p = 0.014). The C7 plumb line of the R group was located more posteriorly than that of the A group (p = 0.023), but was no different from than that of the R+A group (p = 0.422). The location of C7 plumb line did not differ between the three groups (p = 0.068). The spinosacral angle of the R group was significantly smaller than that of the A group (p < 0.001) and R+A group (p < 0.001). Our findings imply that there are two types of degenerative retrolisthesis: one occurs primarily as a result of degeneration in patients with low pelvic incidence, and the other occurs secondarily as a compensatory mechanism in patients with an anterolisthesis and high pelvic incidence. Cite this article: Bone Joint J 2013;95-B:1244–9

Aims. The aim of this study is to test the hypothesis that three grades of sagittal compensation for standing posture (normal, compensated, and decompensated) correlate with health-related quality of life measurements (HRQOL). Methods. A total of 50 healthy volunteers (normal), 100 patients with single-level lumbar degenerative spondylolisthesis (LDS), and 70 patients with adult to elderly spinal deformity (deformity) were enrolled. Following collection of demographic data and HRQOL measured by the Scoliosis Research Society-22r (SRS-22r), radiological measurement by the biplanar slot-scanning full body stereoradiography (EOS) system was performed simultaneously with force-plate measurements to obtain whole body sagittal alignment parameters. These parameters included the offset between the centre of the acoustic meatus and the gravity line (CAM-GL), saggital vertical axis (SVA), T1 pelvic angle (TPA), McGregor slope, C2-7 lordosis, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL, sacral slope (SS), pelvic tilt (PT), and knee flexion. Whole spine MRI examination was also performed. Cluster analysis of the SRS-22r scores in the pooled data was performed to classify the subjects into three groups according to the HRQOL, and alignment parameters were then compared among the three cluster groups. Results. On the basis of cluster analysis of the SRS-22r subscores, the pooled subjects were divided into three HRQOL groups as follows: almost normal (mean 4.24 (SD 0.32)), mildly disabled (mean 3.32 (SD 0.24)), and severely disabled (mean 2.31 (SD 0.35)). Except for CAM-GL, all the alignment parameters differed significantly among the cluster groups. The threshold values of key alignment parameters for severe disability were TPA > 30°, C2-7 lordosis > 13°, PI-LL > 30°, PT > 28°, and knee flexion > 8°. Lumbar spinal stenosis was found to be associated with the symptom severity. Conclusion. This study provides evidence that the three grades of sagittal compensation in whole body alignment correlate with HRQOL scores. The compensation grades depend on the clinical diagnosis, whole body sagittal alignment, and lumbar spinal stenosis. The threshold values of key alignment parameters may be an indication for treatment. Cite this article: Bone Joint J 2020;102-B(10):1359–1367

We investigated the relationship between spinopelvic parameters and disc degeneration in young adult patients with spondylolytic spondylolisthesis. A total of 229 men with a mean age of 21 years (18 to 26) with spondylolytic spondylolisthesis were identified. All radiological measurements, including pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, sacral inclination, lumbosacral angle (LSA), and sacrofemoral distance, were calculated from standing lateral lumbosacral radiographs. The degree of intervertebral disc degeneration was classified using a modified Pfirrmann scale. We analysed the spinopelvic parameters according to disc level, degree of slip and disc degeneration. There were significant positive correlations between the degree of slip and pelvic incidence (p = 0.009), sacral slope (p = 0.003) and lumbar lordosis (p = 0.010). The degree of slip and the LSA were correlated with disc degeneration (p < 0.001 and p = 0.003, respectively). There was also a significant difference between the degree of slip (p < 0.001) and LSA (p = 0.006) according to the segmental level of disc degeneration. Cite this article: Bone Joint J 2013;95-B:1239–43

Aims. To compare the rates of sagittal and coronal correction for all-pedicle screw instrumentation and hybrid instrumentation using sublaminar bands in the treatment of thoracic adolescent idiopathic scoliosis (AIS). Methods. We retrospectively reviewed the medical records of 124 patients who had undergone surgery in two centres for the correction of Lenke 1 or 2 AIS. Radiological evaluation was carried out preoperatively, in the early postoperative phase, and at two-year follow-up. Parameters measured included coronal Cobb angles and thoracic kyphosis. Postoperative alignment was compared after matching the cohorts by preoperative coronal Cobb angle, thoracic kyphosis, lumbar lordosis, and pelvic incidence. Results. A total of 179 patients were available for analysis. After matching, 124 patients remained (62 in each cohort). Restoration of thoracic kyphosis was significantly better in the sublaminar band group than in the pedicle screw group (from 23.7° to 27.5° to 34.0° versus 23.9° to 18.7° to 21.5°; all p < 0.001). When the preoperative thoracic kyphosis was less than 20°, sublaminar bands achieved a normal postoperative thoracic kyphosis, whereas pedicle screws did not. In the coronal plane, pedicle screws resulted in a significantly better correction than sublaminar bands at final follow-up (73.0% versus 59.7%; p < 0.001). Conclusion. This is the first study to compare sublaminar bands and pedicle screws for the correction of a thoracic AIS. We have shown that pedicle screws give a good coronal correction which is maintained at two-year follow-up. Conversely, sublaminar bands restore the thoracic kyphosis better while pedicle screws are associated with a flattening of the thoracic spine. In patients with preoperative hypokyphosis, sublaminar bands should be used to restore a proper sagittal profile. Cite this article: Bone Joint J 2020;102-B(3):376–382

Aims. The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. Patients and Methods. This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. Results. Reduced T5-12 kyphosis (mean -4.3° (. sd. 8.2); p < 0.001), maximum thoracic kyphosis (mean -4.3° (. sd. 9.3); p < 0.001), and lumbar lordosis (mean -5.6° (. sd. 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. Conclusion. Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life. Cite this article: Bone Joint J 2019;101-B:1370–1378

Aim. To evaluate the effect of corrective surgery for adolescent idiopathic scoliosis on pelvic morphology. Introduction. Pelvic incidence increases linearly with age during childhood and adolescence before stabilising in adulthood. Most scoliosis surgery occurs before adulthood. We tested the hypothesis that during growth, scoliosis surgery alters the normal linear relationship between pelvic incidence and age. Methods. One hundred patients with 200 radiographs who had undergone surgery for scoliosis were identified. Thirty-eight patients were excluded due to other diagnoses. All patients had posterior surgery for adolescent idiopathic scoliosis. Pre and post-operative lateral radiographs taken at 6 weeks were assessed. Spino-pelvic indices measured were Pelvic Incidence (PI), Sacral Slope (SS), Pelvic Tilt (PT) and the C7 plumb line. Results. There were 62 patients: 58 females and 4 males. Median age was 14 (range 12-17). Median pelvic parameters pre-operatively were 49, 39 and11 degrees for PI, SS and PT respectively. Post operative median values were 48, 36 and14 degrees for PI, SS and PT. Statistical analysis showed no significant differences in pelvic incidence, pelvic tilt or the C7 plumbline between pre- and post-operative values. There was a significant decrease in sacral slope from a median of 39 degrees pre-operatively to 36 degrees post operatively (p=0.007). There was no statistical difference between these variables when analysed by age or gender, nor were there any correlations between the change in variables. All values fell within the normal ranges for age related spino-pelvic parameters. Conclusion. Corrective surgery for adolescent idiopathic scoliosis does not alter pelvic morphology even in the growing adolescent group. Previous studies have documented the pre and post operative correlation between pelvic geometry and spinal alignment in normal and surgical subjects. This study investigates whether surgery affects pelvic morphology during its developmental stages. This to our knowledge has not been described previously

Aim:. To establish whether there is a direct relationship between pelvic morphology and lumbar segmental angulation in the sagittal plane. Methods:. 40 lateral whole spine radiographs with normal sagittal profiles were reviewed. Pelvic incidence (PI), Lumbar Lordosis (LL), Thoracic Kyphosis (TK) and segmental angulation at each level from L1 to the sacrum were measured (from endplate to endplate) distinguishing the vertebral body and intervertebral disc contribution. Pearson correlation coefficients were used to analyse any relationship between pelvic parameters and segmental angulation. Results:. A strong correlation was found between pelvic incidence and total lumbar lordosis and angulation at cephalad lumbar segments (L12, L23 and L34) P<0.0001 with the increased lordosis primarily (four fifths on average) found at the intervertebral disc. The proportion of total lumbar lordosis contributed at L45 and L5S1 reduced as pelvic incidence increased (P<0.0001). Discussion:. PI can predict segmental angulation. Although the majority of lumbar lordosis is produced at L45 and L5S1, cephalad-lumbar segments sequentially become increasingly important as PI increases. This describes a continuum that allows segmental abnormalities to be identified when compensation in adjacent segments maintains normal total LL. It also paves the way for anatomical reconstruction in degenerative adult deformity based on pelvic morphology. Conflict Of Interest Statement: No conflict of interest

Introduction. Iatrogenic spondylolisthesis occurs infrequently after posterior decompression. Posterior surgery is challenging due to altered anatomy and scarring. Anterior lumbar interbody fusion (ALIF) allows indirect decompression, restoration of lordosis and fusion. Material and Methods. Retrospective review of 6 patients (5 female, 1 male, mean age 64±5.8 years) with iatrogenic spondylolisthesis (5 L4/L5; 1 L4/L5) treated with stand-alone ALIF (Synfix, BMP2). Assessment of pelvic incidence, listhesis, pre- and post-operative ODI, VAS, global lumbar lordosis and segmental lordosis as outcome measurements. Results. The slippage was grade II at L4/L5 in 3 patients and grade I in 2 patients at L4/L5 and 1 patient at L5/S1. Average ODI dropped from 49±11% pre-operatively to 30±9% at 6 and to 25±6% at 12 months follow-up. VAS average dropped from 7±1 to 3±1 at 6 and 12 months follow-up. Average pelvic incidence was 54.6±8.0°. Global lordosis of 44.6±5.2° increased to 49.0±8.6°; Segmental lordosis in L4/5 was increased from 12.1±8.2° to 22.4±3.7° at 6 and 20.5±7.9° at 12 months. Cage migration due to severe osteoporosis occurred in 1 case after 5 months. Conclusion. Anterior interbody fusion offers good stabilization and restoration of lordosis in iatrogenic spondylolisthesis. In our group, ODI and VAS scores were improved. These early results encourage further investigations regarding long-term follow-ups and prospective studies in larger patient groups

Aim:. The purpose of this study was to identify factors (radiographic and MRI) which may be important in determining whether a degenerative spondylolisthesis at L4/5 is mobile. Method:. We identified 60 consecutive patients with a degenerative spondylolisthesis(DS) at L4/5 and reviewed their imaging. Patients were separated into groups on the basis of whether the DS was mobile (group A) or non-mobile (Group B) when comparing the upright plain lumbar radiograph to the supine MRI. We assessed the lumbar lordosis, pelvic incidence, sacral slope, pelvic tilt, grade of the slip, facet angles at L4/5, facet tropism, facet effusion size, facet degenerative score (cartilage and sclerosis values) and disc degenerative score (Pfirrmann) at L4/5. Results:. There were 40 patients in group A and 20 in group B. Mean age for group A was 69.2 years and for group B was 66.2 years. The difference was not significant (p-0.27; 95% CI 2.5–8.7). No significant differences were found between groups for pelvic incidence (p-0.75; 95% CI 4.6–6.3), pelvic tilt (p-0.62; 95% CI 3.2–5.3), sacral slope (p-0.51; 95% CI 3.2–6.5), lumbar lordosis (p-0.46; 95% CI 9.5–4.3), degree of facet tropism (p-0.4) and magnitude of the facet effusions (p-0.1). Facet angle differences between groups approached significance (p-0.058; 95% CI 0.1–6.7). Significant differences between groups were found in cartilage degenerative score (p-0.002), facet sclerosis grade (p-0.00) and disc degenerative score (p-0.00). In group B 10 out of 20 (50%) reduced fully and were not apparent on the MRI only. Conclusions:. Sagittal pelvic parameters do not play a significant role in differentiating between mobile and non-mobile DS at L4/5. Mobile DS tends to be associated with more sagittally orientated facets, lower Pfirmann grade, lower facet cartilage and sclerosis degenerative scores. Standing plain lumbar radiographs are essential in all patients over the age of 40 years in order not to miss up to 17% of DS at L4/5. Conflict Of Interest Statement: No conflict of interest

Spinal deformities are a common feature of Marfan’s syndrome and can be a significant cause of morbidity. The morphology of the scoliosis associated with this condition was previously described by Sponseller, but no correlation with the pelvic parameters has been seen. We performed a retrospective radiological study of 58 patients with scoliosis, secondary to Marfan’s syndrome and related the findings in the thoracolumbar spine to the pelvic parameters, including pelvic version (tilt), pelvic incidence and sacral slope. Our results showed marked abnormalities in the pelvic values compared with those found in the unaffected population, with increased retroversion of the pelvis in particular. In addition we found a close correlation between the different patterns of pelvic parameters and scoliosis morphology. We found that pelvic abnormalities may partially dictate the spinal disorders seen in Marfan’s syndrome. Our results supplement the well-established Sponseller classification, as well as stressing the importance of considering the orientation of the pelvis when planning surgery

Aims

A variety of surgical methods and strategies have been demonstrated for Andersson lesion (AL) therapy. In 2011, we proposed and identified the feasibility of stabilizing the spine without curettaging the vertebral or discovertebral lesion to cure non-kyphotic AL. Additionally, due to the excellent reunion ability of ankylosing spondylitis, we further came up with minimally invasive spinal surgery (MIS) to avoid the need for both bone graft and lesion curettage in AL surgery. However, there is a paucity of research into the comparison between open spinal fusion (OSF) and early MIS in the treatment of AL. The purpose of this study was to investigate and compare the clinical outcomes and radiological evaluation of our early MIS approach and OSF for AL.

Aims

Postoperative complication rates remain relatively high after adult spinal deformity (ASD) surgery. The extent to which modifiable patient-related factors influence complication rates in patients with ASD has not been effectively evaluated. The aim of this retrospective cohort study was to evaluate the association between modifiable patient-related factors and complications after corrective surgery for ASD.

Aims

Symptomatic spinal stenosis is a very common problem, and decompression surgery has been shown to be superior to nonoperative treatment in selected patient groups. However, performing an instrumented fusion in addition to decompression may avoid revision and improve outcomes. The aim of the SpInOuT feasibility study was to establish whether a definitive randomized controlled trial (RCT) that accounted for the spectrum of pathology contributing to spinal stenosis, including pelvic incidence-lumbar lordosis (PI-LL) mismatch and mobile spondylolisthesis, could be conducted.

Background:. Outcome after traumatic spinal fracture is difficult to predict. Some patients have ongoing pain while others make a good recovery and there is therefore considerable debate as to which fractures should be treated operatively. Delayed operations for ongoing pain post fracture are more expensive with a longer recovery. The sagittal balance of the spine may predict patient outcomes post fracture. Aim:. Identify subjects with stable spine fractures not requiring acute fixation and compare their sagittal parameters measured on initial standing x-ray with whether or not they have ongoing pain. Methods:. A retrospective review was undertaken of patients presenting with a spine fracture to North Bristol Trust over a five year period. Sagittal parameters on initial standing x-rays were measured. The presence or absence of pain at last follow up was recorded. Results:. 399 fractures were identified. 100 were taken to theatre for acute fixation. Only 120 of those remaining had x-rays available which allowed full sagittal parameters to be measured. Clinical outcomes were available on 97 of these subjects. The measurement of pelvic incidence was not found to be significantly different in the two groups (p=0.218). The differences in pelvic tilt between those with and without pain was significant (p=0.004). Conclusion:. A lower pelvic tilt correlates with pain post fracture. Whether this is predictive of pain or not is unclear. Further investigation is indicated to examine the clinical outcomes and economic impact on subjects presenting with a fracture of the spine as well as the economic impact to the health service

Aims

The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment.

To describe a staged surgical technique to correct significant progressive sagittal malalignment, without the need for 3-column osteotomy, in patients with prior long thoracolumbar instrumentation for scoliosis and to evaluate the radiographic and clinical outcome from this surgical strategy. A small cohort study (n=6) of patients with significant sagittal malalignment following extensive thoracolumbar instrumented fusions for scoliotic deformity. Radiographic parameters analysed included pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis and sagittal vertical axis. Clinical outcome measures collected included EQ-5D, ODI, SRS 22 and VAS Pain Scores. 3 patients had 2-stage anterior release and instrumented fusion followed by a posterior instrumented fusion 3 patients with a large sagittal plane deformity had a 3-stage surgical technique. All patients achieved an excellent correction of sagittal alignment, with no surgical complications and excellent health related quality of life (HRQOL) outcome measures at follow-up. There was no symptomatic non-unions or implant failures including rod breakages. We present a safe and effective surgical strategy to treat the complex problem of progressive sagittal malalignment in the previously instrumented adult deformity patient, avoiding the need for 3-column osteotomies in the lumbar spine